Conventional passenger conveyor devices such as mechanical stairs or moving walkways include a chain of steps or pallets which shift in a loop to provide continuous movement along a specific trajectory. The steps or pallets are connected to said chain link loop of steps or pallets acting together with an actuation system. The actuation system normally consists of a chain of steps or pallets, actuation gear wheels, a shaft and an electric drive motor. The drive motor actuates the drive gear wheel which conveys movement to the links of the chain of steps or pallets. While the links of this chain move, the steps or the pallets move as desired.
To assure small speed fluctuation and to minimize the polygon effect in the conventional conveyor system, a large number of teeth are required on the actuation gear wheel and this leads to a large gear wheel diameter. The large gear wheel diameter increases the size of the upper and lower heads of the system, making a deep pit for placing the walkway necessary. The link between the pallet and the chain of pallets is commonly located under the surface of the pallet. Given that the gap between two consecutive pallets is limited to meet safety requirements, the transition radius in inclined walkways is limited.
Other types of actuation mechanisms engaging the conveyor at intermediate points have been proposed, such as those shown in U.S. Pat. No. 3,677,388, WO2004/063078A1 and WO2004/054919A1. The common feature of the previously mentioned inventions is that they all propose using a linear actuation system to move any type of chain connected to the steps or pallets and, therefore driving the chains of pallets or steps of the conveyor system. Nevertheless, the metal to metal contact between the chain of the linear actuation system and the chain links connected to the steps or pallets makes noise. The general configuration proposed in these documents does not allow the possibility of reducing the dimensions of the conveyor. The general dimensions of conventional walkways are much larger than those which can be provided by the present invention.